Klaric : Safe measurement of currents and voltages in hybrid systems

KLARI-MOD MC 2-1000V provides two galvanically isolated measuring channels, each equipped with an own ASIC. This enables measuring two channels in parallel and independent from each other as follows:
2x current or
2x voltage or
1x current and 1x voltage.

The ASIC for measured-value capture processes input signals from ±7.5 to -300/+720 mV in five ranges direct with a resolution of +/-15 bit. The signal amplifier is built-in so there is no need for external amplification of the voltage signals that would cause additional amplification errors.

The switchable Autorange function can automatically adapt the five available measurement ranges to the current measured value during runtime.

Sampling times for each ASIC can be selected in increments between 250 µs and 128 ms. Using the single-channel mode the sampling time can be reduced to 125 µs, which means that 8000 values per second will be measured. Thus allows current measurement on the AC circuit.

All measured values are integrated, averaged and output as one measured value within the sampling time.

The measurement system can be configured with a PC software tool, the CAN identifier and CAN baud rate can be selected as can different data output modes. The measured values are sent in 24 bit format via CAN or RS232. As well as the probe type and measurement range, a timestamp is sent which is independent of the timestamp of the receiving station.

The selectable difference mode allows minimizing the data rate without gaps. The integrated CAN termination is disengageable via software.

To ensure a safe measurement the circuit design provides continuous insulation of 1kV between both channels as well as between the measuring circuit and data output.

A number of insulated pluggable probes for current and voltage enable the optimal adaption to the measuring task. The true resistance measured on the test bench is transferred to the measurement module and used to calculate the currents. This concept allows a measurement module to be individually fitted with different probes. The measurement module automatically identifies the probe, the measured values are correctly calculated and output without the manual input of correction factors.

For measuring current low resistance precision shunts are looped into the measurement circuit. These shunts are mechanically robust and combine high temperature resistance with minimal temperature drift. Using a 1mΩ shunt a measuring range from -300 to +720 A can be covered with a resolution of 250 µA/Bit in the lowest range.

Individual application solutions allow the safe use of this technology in vehicles.

In order to guarantee insulation quality during the volume production of modules, each module and each probe must pass an insulation resistance test between its measuring circuit and data output as part of final inspection and testing: There must be no flashover between the circuits and between measuring circuit and casing when a test voltage of 6kV is applied for 60s.

Note: The above text is the public part of the press release obtained from the manufacturer (with minor modifications). EETimes Europe cannot be held responsible for the claims and statements made by the manufacturer. The text is intended as a supplement to the new product presentations in EETimes Europe magazine.